1. Field of the Invention
The present invention relates to a syringe, and more particularly to a syringe including a needle safely receiving structure for safely receiving the needle after use and for preventing the syringe from being used again after use.
2. Description of the Prior Art
Typical syringes may be used to draw blood, or may be used to inject medicine into human bodies. Due to the acquired immune deficiency syndrome (AIDS) and the other contagious diseases, the needles of the syringes, and even the syringes themselves, should not be used again and should be discarded right after use, for safety purposes.
U.S. Pat. No. 5,951,491 to Wu discloses one of the typical syringes including a piston rod that may be broken and disengaged from the piston after use. However, the needle may not be safely received in the syringe housing and may also be exposed and may also be contacted or hurt the other people inadvertently after use. The typical syringes may be used again after the first use.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional syringes.
The primary objective of the present invention is to provide a syringe including a needle safely receiving structure for safely receiving the needle after use and for preventing the syringe from being used again after use.
In accordance with one aspect of the invention, there is provided a syringe comprising a barrel including a front portion and a rear portion, a nozzle received in the front portion of the barrel and including a front portion, a needle attached to the front portion of the nozzle and extended outward of the barrel, a stem including a piston slidably received in the barrel and movable toward and away from the nozzle, and the piston including latch means for latching to the nozzle and to move the nozzle inward of the barrel after the latch means has been engaged into the nozzle. The nozzle and thus the needle may be pulled inward of the barrel after use, such that the nozzle and the needle may be prevented from being used again after use.
The barrel includes means for preventing the nozzle from being moving outward through the front portion of the barrel. The preventing means includes a peripheral shoulder formed in the front portion of the barrel for engaging with the nozzle and for preventing the nozzle from being moving outward through the front portion of the barrel.
The barrel includes means for detachably securing the nozzle to the barrel. The detachably securing means includes a peripheral rib formed in the front portion of the barrel, the nozzle includes an outer peripheral recess formed therein for receiving the peripheral rib of the barrel and for detachably securing the nozzle to the barrel.
The nozzle includes a chamber formed therein, the latch means of the piston includes a latch extended from the piston for engaging into the chamber of the nozzle.
The nozzle includes means for retaining the latch in the chamber of the nozzle. The latch includes an orifice formed therein for increasing a deformability of the latch.
The nozzle includes at least one groove formed therein for defining at least one spring blade therein and for facilitating an engagement of the latch into the chamber of the nozzle.
The stem includes means for detachably securing the stem to the piston. The detachably securing means of the stem includes at least one coupling member coupled between the stem and the piston for allowing the stem to be disengaged from the piston when the stem is bent relative to the piston.
The detachably securing means of the stem includes an extension extended from the piston, and at least one coupling member coupled between the stem and the extension for allowing the stem to be disengaged from the extension when the stem is bent relative to the extension.
The extension includes an enlarged head provided thereon, the detachably securing means of the stem includes at least one coupling member coupled between the stem and the enlarged head for allowing the stem to be disengaged from the enlarged head when the stem is bent relative to the enlarged head.
A device is further provided for preventing the piston from being moving outward and disengaged from the rear portion of the barrel and includes at least one catch extended from the piston for engaging with the barrel and for preventing the piston from being moving outward and disengaged from the rear portion of the barrel.
The piston includes at least one spring leg extended therefrom for supporting the catch. The barrel includes a peripheral flange extended inward of the rear portion thereof for engaging with the catch and for preventing the piston from being moving outward and disengaged from the rear portion of the barrel.
Further objectives and advantages of the present invention will become apparent from a careful reading of a detailed description provided hereinbelow, with appropriate reference to accompanying drawings.